1. Field of the Invention
This invention relates generally to liquid handling apparatus, and more particularly to a liquid handling apparatus that is capable of several modes of operation, including fractionating, sampling, dispensing, diluting and other functions.
2. Description of the Prior Art
Various liquid handling systems are known. One of the most common of such liquid handling systems is a fractionator which is designed to deposit a predetermined volume of a particular liquid into each of an array of containers, such as test tubes, disposed in a rack located beneath the dispensing tube of the fractionator.
Other liquid handling devices such as dispensers, samplers and diluters are also known; however, all of them are limited in their capabilities, thus requiring different devices to be used for different applications. Moreover, the sampling or dispensing tube in such devices is limited in its movement capability, with most of such devices having liquid handling tubes or dispensing heads that are movable in only a few simple patterns. In addition, the liquid handling tubes or dispensing heads are movable in only two directions in a horizontal plane with respect to the array of containers, thus precluding the withdrawal of liquid from one container for deposit into another.